Is this why America has more Prii than Europe?

There seems to be some misunderstanding, or at least old perceptions, of diesel emissions.

Diesel do tend to have higher PM and NOx emissions, but typically have, and have had, lower hydrocarbon and carbon monoxide emissions.

Current regulations in the U.S. require significant reduction of both PM and NOx emissions from diesel engines. Granted, there is a significant cost penalty, but the emissions are now approaching trivial levels.

You also have to account for higher "upstream" emissions of gasoline compared to diesel fuel, especially hydrocarbon emissions (VOCs), due to the volatile nature of gasoline. From a "well-to-wheel" (WTW) perspective, diesels in general are no higher with respect to NOx and PM2.5 emissions than gasoline vehicles in general according to Argonne National Laboratory's "GREET" model, and are lower with respect to HC emissions...








(Wang, "GREET Life-Cycle Analysis of Vehicle/Fuel Systems." Argonne National Laboratory)


I conducted a modeling exercise of a 2011 PZEV-certified gasoline VW Jetta vs. a 2011 ULEV-certified Jetta TDI, using the CARB cert data for the "pump-to-wheel" (PTW) portion of the emissions and the latest version of the GREET model (v1.8d.1) for the "well-to-pump" (WTP) portion of the emissions, and the WTW emissions (HC+NOx, CO, PM, SOx) are actually LOWER across the board for the TDI.

 

"rom a "well-to-wheel" (WTW) perspective, diesels in general are no higher with respect to NOx and PM2.5 emissions than gasoline vehicles in general according to Argonne National Laboratory's "GREET" model, and are lower with respect to HC emissions..."

Try that comparison against a Prius, rather than a "general" ICE.

 

I have long maintained that the gene pool in the US was different than in Europe as a result of self selection because people who were satisfied with the status quo and were risk adverse didn't take off and move to new continents.

The risk adverse and status quo favorers didn't get in covered wagons and cross the US or sail around the horn to get to the West Coast either.

Now that transportation is easy and low risk, the results of that migration are being muddied, but differences in approach to life can still be seen.

 

Which "non-general" diesel vehicle would you like to compare it to?

 

You think satisfaction is genetic ? If I ate a nice breakfast did my genes change ?

 

To put it in the breakfast context....

People who were satisfied with watery gruel for breakfast stayed put. Those who weren't satisfied went looking elsewhere for a better breakfast even though they knew it might mean they didn't get any breakfast or worse yet might become something's breakfast.

 

No, but your gene expression may well have.

 

then, why are we always whining over here about how everything is better in europe?

 

At the risk of being judged a regionalist, in terms of personal freedom, a peaceful and just society, a stable economy, and gorgeous scenery, it's pretty darned nice here. Admittedly, I haven't travelled far and wide, but the more I hear from those who have, the luckier I feel to have been born here. There are places I'd like to visit - a tropical beach would be lovely right about now - but this will always be home.

 

That has exactly zilch to do with with xs' contention that the current European sourced american gene pool is different that modern day Europe because immigrants were dissatisfied with their station in life.

Give it up guys. The contention is silly

 

I think the Toyota is just better accepted as a car company here than in Europe. If BMW had the Prius, it would be all of the rage in Europe and much less so here.

 

Hi Wxman and SageBrush,

As Sagebrush points out the Prius has dramatically better CO and HC emissions than a general ICE Otto Engine car. I think I remember somewhere on the order of 15 % the levels of the typical ICE car. The Argonne Hybrid Car levels, are not the Prius levels.

But, I have to admidt to being somwhat ignorant to the GREET model beyond that comment.

But seriously, the practical aspects of the TDI emissions are just not there yet, when my sinuses are clogging up, and eyes tearing up, when I am sitting for 5 minutes at a train crossing down wind from a modern, new TDI, and not when I am next to modern gasoline cars idling away.

And, what value is it to say that diesel fuel has less VOC emisions, when we are not going to be getting rid of the gasoline production and delivery infrastucure in the the near future?

The Prius is excellent in VOC emissions. Its one of the main things that Toyota worked hard on. The 2nd Gens had the rubber lined gasoline tank. And blaming the Prius for the distribution system emissions is not really of value, as like I said above nobody is shutting down gasoline distribution in the USA any time soon. By using a Prius, less gasoline needs to be distributed, and thus less VOC emitted. And besides, the EPA could ask the distribution system to improve its VOCs.

Gasoline is not the only fuel that will burn in an Prius, or other gasoline cars. Butanol, which is much lower in VOC than gasoline, but has nearly the same fuel energy content, and can be burned at any gasoline ratio mix in modern cars.

 

Hi Donee,

That's true and I'm not disputing that. I'm just disputing that the current generation of "clean" diesel engines is significantly more polluting in general than the current generation of gasoline engines.

I don't think the TDI you noticed was a 2009+ model year vehicle. The current generation of "clean" diesel cars have no noticeable odor, even right at the exhaust pipe.

Wayne Gerdes, administrator of cleanmpg.com, recently posted on that website that during his visit to Argonne National Laboratory, PM and NOx exhaust emissions from a 2009 VW Jetta TDI were so low that they couldn't be measured by the most sensitive instrumentation ANL was able to obtain ( Lexus CT 200h Performance by the Numbers - CleanMPG Forums - please see his response to my inquiry below main post).

GREET does. VOC emissions are correlated to gasoline consumption, so theoretically, if you displace some of the gasoline with far less volatile diesel fuel, VOC emissions would decrease accordingly.

There's actually very little gasoline-range hydrocarbons that come naturally in a barrel of crude oil. Most crude consists of middle distillates and heavier, and that heavier fraction is increasing all the time as the "light, sweet" crude oil is used up. Our (U.S.) refineries are configured to maximize gasoline production over middle distillate (e.g., diesel fuel), but it doesn't necessarily have to be that way.

GREET also takes into account all of the emissions from diesel engines that are used as generators at well heads, diesel trucks to deliver gasoline to gas stations, etc.

Again I'm not disputing that, and I'm not "blaming" the Prius for anything. I'm just taking issue with some of the comments about how bad diesel emissions are, even with the current crop of "clean" diesel.